Sealant spray applicator system and method employing same

Abstract

Method and system for applying liquid sealant in holes of a structural member prior to installing fasteners in such holes, which comprises mixing air with a liquid sealant, spraying a controlled amount of the resulting air-sealant mixture into the holes and depositing liquid sealant therein, and impinging an elevated pressure air stream on the deposited liquid sealant to spread the sealant out and produce a thin layer of sealant in the holes. A system for carrying out the method comprises a spray gun having separate air and liquid sealant paths which meet at the spray nozzle of the spray gun to achieve the mixing of air with the liquid sealant. The liquid spray system also includes a sealant applicator controller which is arranged to activate a series of timers and valves to provide controlled flow of high pressure air and liquid sealant to the nozzle for mixture therein, and spraying to form the sealant deposit, and to provide for continued high pressure flow of air on the layer of sealant deposit to spread the sealant and produce a thin sealant layer.

What is claimed is: 
     
       1. In the method for applying liquid sealant in holes of a structural member prior to installing fasteners in such holes, the improvement which comprises the steps of: mixing air with a liquid sealant,   spraying a controlled amount of the resulting air-sealant mixture into the holes and depositing liquid sealant therein, and   impinging an elevated pressure air stream on the deposited liquid sealant to spread the sealant out and produce a thin layer of said sealant in said holes.   
     
     
       2. The method of claim 1, including providing a spray gun having a spray nozzle and separate air and liquid sealant paths which meet at the spray nozzle to produce said mixing of air with said liquid sealant, and positioning said nozzle adjacent to but out of contact with said holes for said spraying of the resulting air-sealant mixture into said holes. 
     
     
       3. A method for applying liquid sealant in holes of a structural member prior to installing fasteners in said holes, which comprises: providing a sealant applicator controller and a spray gun having a spray nozzle positioned adjacent to but out of contact with said holes, a first timer activated by said controller to permit high pressure air to blow through the spray gun, and a second timer activated through said controller to permit a flow of liquid sealant under pressure through said spray gun,   passing said high pressure air to said nozzle for a first predetermined period of time set by said first timer, and passing said liquid sealant to said nozzle for a second predetermined period of time set by said second timer, said first predetermined time period being longer than said second predetermined time period,   mixing said high pressure air and liquid sealant in said nozzle to atomize same,   spraying a controlled amount of the resultant atomized air-liquid sealant mixture into the holes and depositing liquid sealant therein, and   after said second predetermined time period has passed and liquid sealant ceases to flow to said nozzle, impinging the high pressure air stream alone for the remainder of said first predetermined time period from said nozzle onto the deposited liquid sealant to spread the sealant out and produce a thin layer of said sealant in said holes, and prevent dripping.   
     
     
       4. The method of claim 3, including providing a delay timer activated by said controller, to delay activation of said second timer for a third period of time and permitting the high pressure air to begin flowing through the spray gun for said third predetermined time period before the liquid sealant is permitted to flow, said first predetermined time period being longer than both said second and third predetermined time periods. 
     
     
       5. The method of claim 4, wherein said first timer and said delay timer are simultaneously activated by said controller. 
     
     
       6. The method of claim 3, wherein said first timer and said second timer are simultaneously activated by said controller. 
     
     
       7. A system for applying liquid sealant in holes of a structural member, which comprises: a spray gun having a spray nozzle,   means forming separate air and liquid sealant paths to said spray nozzle for mixing said air and sealant to form an air-sealant spray adapted to be directed into said holes,   a sealant applicator controller,   a source of high pressure,   a first timer actuated by said controller,   a first valve means actuated by said first timer to permit said high pressure air to flow to said spray nozzle,   a source of liquid sealant,   a second timer activated by said controller,   a second valve means actuated by said second timer to permit a flow of liquid sealant to said spray nozzle,   said first timer being controllable with respect to said second timer to permit continued flow of high pressure air to said nozzle and adapted to be impinged on the sealant deposit in said holes after said second timer has deactivated said second valve means to cease flow of liquid sealant to said spray nozzle.   
     
     
       8. The system of claim 7 including a delay timer associated with said second timer, and activated by said controller, to delay activation of said second timer for a predetermined period following activation of said first timer, to permit high pressure air to flow to said spray nozzle alone prior to flow of liquid sealant to said spray nozzle. 
     
     
       9. The system of claim 8, said controller being arranged for simultaneous activation of said first timer and said delay timer. 
     
     
       10. The system of claim 7, said source of liquid sealant being a pressurized sealant reservoir. 
     
     
       11. The system of claim 7, said first timer and said second timer being simultaneously activated by said controller.